Problem: Michael is 3 times as old as William and is also 14 years older than William. How old is William?
Answer: We can use the given information to write down two equations that describe the ages of Michael and William. Let Michael's current age be $m$ and William's current age be $w$ $m = 3w$ $m = w + 14$ Now we have two independent equations, and we can solve for our two unknowns. Since we are looking for $w$ , and both of our equations have $m$ alone on one side, this is a convenient time to use elimination. Subtracting the second equation from the first equation, we get: $0 =$ $3w$ $-$ $ (w + 14)$ which combines the information about $w$ from both of our original equations. Solving for $w$ , we get: $2 w = 14$ $w = 7$.